New LVH Engine :) - used to be flat battery....

What was the GSF code for the starter. When I called yesterday the person I spoke with had no clue.

 

If you put a cable from battery direct to starter where on starter do you put it?

There seems to be a yellow cable or red.

 

Any idea what this relay is for - seems to have something to do with the starter (hot start?)

 

I think you should look at the gearbox earth strap. I've had ones that look A.O.K. but given a tug crumbled to dust...
From your symptoms as described it can't really be anything else.

 

It's a hot start relay by the looks, looks like the connections might need a clean or better still put in the engine bay to keep it away from the road crud

 

if you put one meter lead on the battery earth terminal and the other on a good earth point on the engine block and get someone to crank the engine on the ignition switch, the voltage reading should be no more than 0.5v . If its more than this you have a bad earth. Its called volt dropping. You can also do the same between the battery positive and the main starter terminal , and between both solonoid main terminals.Its the only way to check for poor connections.

 

heres a better explanation http://www.aa1car.com/library/voltage_drop_testing.htm

 

I have no idea where my paperwork is after the move, they only list 1 for an auto on the website tho

 

It's part number 901VG0090 but before you buy it check, and if necessary replace, the earth straps from the battery to the body and from the body to the gearbox - as mentioned earlier.

 

The fact that a PO has fitted a so called hot start relay would say that there are other issues, earth straps on gearbox already mentioned and probably new starter time. But check all earths first(they are cheaper and easier to do)

 

It looks like the red/black and yellow are both on the same terminal point so from the bolt that goes to the battery and one of those terminals I would disconnect both of them first. But it is sounding like an earthing problem as Zed says.

 

If it starts with an external battery on battery + and the tow bar then the earth connection from the battery must be bad. Jump starting like that is bypassing the battery earth.

From your pictures, the yellow wire seems to be the ignition switch feed to the starter solenoid, via the hot start relay.

The red/black is the original starter wire from the ignition switch in VW circuit diagrams - there must be something strange going on because the hot start relay is being energised by a thin green wire from the pictures.
Pull this one off and take a wire to battery plus to see if it tries to start

Because there is a hot start relay , another possibility is the annoying one that the ignition switch wears out so that the power to the ignition is turned off when the starter motor is running because the contacts are burnt. If you get the engine spinning fast enough then let the key go it may start when the key is released in that case.

As an aside - The chocolate block connector near the starter motor is likely to corrode and provide the same trouble that the hot start relay is trying to prevent.
When you get it working then you need to sort the strange hot start relay wiring, or at least sort out why the red/black was considered on your bus as being incapable of driving the hot start relay directly.

On my bus, changing the ignition switch and the starter motor cured the problem caused by the ignition switch being burnt through years of use, and the starter motor solenoid occasionally refused to pull in even when given a feed direct from the battery.

 

Just an update to this....

Starting has been fine since and is now the least of my worries.

There's still a rattle somewhere from the engine compartment once warmed up.

I've been speaking with @Paul Weeding to resolve the issue but there's only so much Paul can do over the phone.

It's now with a garage and we'll see what they say.

 

Garage has just called to say the problem is with the crankshaft.

 

Yup bugger in deed.

Been on phone to Paul to get an engine built for August.

Just need to visit bank for a loan now

 

Rip the heart out of it and stick a diesel in it.

I would /will if my engine gives up the ghost.